Left paraduodenal hernia leading to ileal obstruction

Left paraduodenal hernias are a rare cause of abdominal pain or obstruction. However, because there is high associated mortality (20 %), prompt and accurate diagnosis is essential. Because internal hernias are not detectable on physical examination, imaging is relied upon for pre-operative diagnosis. Although both computed tomography and barium studies demonstrate left paraduodenal hernias as a cluster of bowel located posterior to the stomach and to the left of the distal duodenum with absence of the normal interdigitation between loops, the findings may be subtle. Knowledge of these findings can avoid an unnecessary delay in diagnosis. We present the case of a 15-year-old girl with a left paraduodenal hernia, where initial CT and barium studies demonstrated nonobstructed jejunum within the hernia sac. Two weeks later a repeat study showed obstructed distal ileum, rather than proximal jejunum, within the sac.